<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .focus ol{
            position: absolute;
        }
        .focus{
            width: 100%;
            height: 170px;
            position: relative;
            padding-top: 44px;
            overflow: hidden;
        }
        .focus ul li{
           float: left;
           list-style: none;
           width: 20%;
        }
        .focus img{
            width: 260px;
            height: 170px;
        }
        
        .focus ul{
            overflow: hidden;
            width: 100%;
        }
        .focus{
            position: relative;
        }
        .focus ol li{
            display: inline-block;
            width: 5px;
            height: 5px;
            background: red;
            list-style: none;
            border-radius: 4px;
        }
    </style>
</head>
<body>
    <div class="focus">
        <ul>
            <li><img src="./img1.jpg"/></li>
            <li><img src="./img5.jpg"/></li>
            <li><img src="./img3.jpg"/></li>
            <li><img src="./img4.jpg"/></li>
        </ul>
        <ol>
            <li class="box"></li>
            <li></li>
            <li></li>
            <li></li>
        </ol>
    </div>
</body>
</html>